This relates generally to integrated circuits, and more particularly, to ways of distributing power in programmable integrated circuits.
Programmable integrated circuits are a type of integrated circuit that can be programmed by a user to implement a desired custom logic function. In a typical scenario, a logic designer uses computer-aided design (CAD) tools to design a custom logic circuit. When the design process is complete, the tools generate configuration data. The configuration data is loaded into memory elements (sometimes referred to as configuration memory cells) to configure the device to perform the functions of the custom logic.
During normal operation of a programmable device, loaded configuration memory cells produce static output signals that are applied to the gates of transistors (i.e., pass transistors). The configuration memory cell output signals turn some pass transistors on and turn other pass transistors off. This selective activation of pass transistors on the programmable device customizes the operation of the device so that the device performs its intended function.
Programmable integrated circuits typically include a large amount of logic resources so as to be able to accommodate a wide range of user applications. As a result, programmable integrated circuits have a complex interconnect fabric for routing user signals on and off chip. At the same time, it is important to supply power evenly to each of the logic resources without suffering from undesired IR drop. As the amount of logic resources and the power density per unit area increases with each new generation of semiconductor devices, it becomes increasing challenging to route the user signals and to supply power supply voltages to the different logic resources on a programmable integrated circuit without increasing cost.